A wide variety of keyed locks or locking mechanisms exist for preventing unauthorized or unwanted entry and/or use of various items and devices including without limitation vehicles, houses, drawers, doors, and the like. While conventional keyed locks and locking mechanisms are generally effective in preventing such unwanted entry and/or use, certain tools and methods have been devised to defeat or overcome the effectiveness of keyed locks in order to forcefully gain entry to and/or use of the locked item.
One well-known manner of overcoming a lock is to pick the lock. Picking a lock requires a great deal of knowledge about the internal workings of the particular lock being picked, and is often relatively time consuming. In addition, locks are continually being improved to make the process of picking certain types of locks extremely difficult, if not altogether impossible. Due to the inherent challenges of picking a lock, certain groups having primarily malicious intentions (most notably car thieves) have devised other commonly used methods for overcoming a lock. By inserting a rigid item (such as a screwdriver) into the lock instead of the appropriate key, and subsequently applying a sufficient torque to that item, many locks can be overcome by force. Such locks typically fail in one of two manners when forced as just described. In a first failure mode, the internal components of the lock (e.g. the lock tumblers, the lock cylinder, and the like) are broken such that the lock cylinder can be rotated with respect to the lock housing. Generally, rotation of the lock cylinder is all that is required to defeat many locks. In a second failure mode, the internal lock components remain intact while the lock housing itself breaks free of the structural item to which it is secured (e.g. a vehicle steering column or vehicle door). Oftentimes, dislodging the lock housing in this manner and rotating the entire lock assembly has the same effect as rotating the lock cylinder with respect to the housing, resulting in the lock being defeated.
In order to prevent the defeat of a lock by forcefully rotating the lock as just described, some lock designs employ strengthened lock components and strengthened connections between the lock and the object to which the lock is secured. However, these design changes have had limited success because the resulting locks are still subject to damage by increasingly forceful attempts to overpower the lock, and are often excessively robust and expensive to manufacture and install. Furthermore, strengthening of certain lock components can require a subsequent strengthening of other lock components, resulting in a costly and on-going cycle of lock re-design in an attempt to eliminate the “weakest link” in the lock system.
Other attempts to protect keyed locks and locking mechanisms from being overpowered include the development of freewheeling locks. Freewheeling locks are constructed such that rotation of the lock cylinder with substantially any item other than the correct key inserted causes the lock cylinder to disengage from those lock components needed to unlock the lock (e.g., a lock drive mechanism). In this way, forced rotation of the lock cylinder does not result in unlocking or overcoming the lock.